Final answer:
The equation represents a circle in standard form and by taking the square root of 169, we find that the radius of the circle is 13 units.
Step-by-step explanation:
The equation (x-3)² + (y+7)² = 169 represents a circle in standard form. The general equation for a circle centered at (h, k) with radius r is (x - h)² + (y - k)² = r². Comparing this to our given equation, where 169 is equal to the radius squared (r²), we can find the radius by taking the square root of 169, giving us a radius of 13. Therefore, the radius of the circle is 13 units.